Jacques Henri Lartigue's The proof of color sheds light on a little-known aspect of the iconic photographer's work: his fascination with the stereoscopic Autochrome - one of the first color photographic processes just introduced. From 1912 to 1927, and then more than a decade later, in 1946, Lartigue produced 300 autochromes, 90 of which are still intact today, presented here for the first time in their entirety and in their original format. This process was a formidable tool for exploration, and renewed his relationship with the medium, in contrast to his work on speed. More attentive to the composition of the image and the development of a broad chromatic palette, the photographer takes on the posture of a painter rather than an instantaneous artist.

The visual corpus is introduced by an essay written by Marion Perceval entitled The Absolute Impression of Reality followed by the text Lartigue's "Tango" Sweater of curator and photography historian Kevin Moore, which help to grasp the importance of the corpus and its impact on the history of color photography, as well as the resonance it continues to have. Several illustrated notes at the end of the book explore, through quotations and analysis, the evolution of the photographer's interest in Autochrome, and the questions it raises.